1. Field of the Invention
The present invention relates to a stopwatch for measuring an elapsed time and, more particularly, to a stopwatch capable of storing a target time in a memory and providing an alarm when the elapsed time is close to or reaches the target time.
2. Description of the Related Art
A stopwatch having a target time function capable of setting a target time and generating an alarm when a measurement time reaches the target time or displaying a time difference between target and measurement times has been conventionally developed. For example, U.S. Pat. No. 4,831,605 describes a stopwatch of this type. Although an arbitrary target time can be set in such a stopwatch, the target time must be key-input and stored in a memory by operating target time input keys.
Even when a target time is set beforehand, however, a measurement result obtained by actual time measurement is sometimes largely different from the target time.
For example, although a user is apt to run 10 km in 40 minutes, it sometimes takes 60 minutes for him or her to run 10 km because a lot of slopes are present. In this case, the user must correct the target value before he or she runs next time. In order to set a target time in a conventional stopwatch, however, a user must record first measurement data in a notebook or the like, set the stopwatch in a target time set mode, and then key-input the target time while checking the measurement data recorded on the notebook or the like.
In a motor car race, for example, since cars run around the same racing course a number of times, pit crews must give instructions about, e.g., an increase and decrease in a speed, a delay, and an order to a driver or prepare for gas replenishment or tire exchange for each lap. If it can be predicted that it takes three minutes, for example, for a motor car to run the circuit once, a timing in which the car passes before a pit can be determined on the basis of a target time of three minutes. If, however, the car is in good condition and can run faster, it may pass the pit at a speed of less than three minutes per lap. In this case, the target time must be reset. Otherwise, the pit crews sometimes fail to give the various instructions as described above or may require a long time in gas replenishment or tire exchange because a preparation time is short.
In a conventional stopwatch with a target time function, however, a target time must be set beforehand by a key-input operation, resulting in a very cumbersome target time set operation.